Hi everyone, I have an issue with shipping and taxes not working in the cart. No matter what you enter on the region/state and postcode it throws up the errors "Please select a region / state!" and "Postcode must be between 2 and 10 characters!". The shipping works fine when you go to checkout however.

The most generated errors being found on Opencart forum originates from contributed programming. The increased post counters are caused by redundancies of the same solutions that were already provided prior.

I've seen this issue before if you have another shipping estimator on that page, or another module that uses the same ID's for the HTML elements. When you estimate, it gets the values from the *other* module, which are blank --- that's why it doesn't work.

Try checking your cart page source code to see if you can find other elements that have the ID "postcode", and see if that leads you to the right module. You can then disable/remove it from that page, so it doesn't affect the normal shipping estimator.